Earthquake



Introduction3

General Overview3

Methods/Tools Of Study4

Discovery5

Unanswered Questions5

Conclusion6

Bibliography7

Earthquake

Introduction

Natural disaster is an event caused by natural processes of Earth for example Earthquake, tsunami and volcanoes. Its effects include loss of life and property damage of which the magnitude depends on the effected population or time it takes to recover. Number of people affected by these disasters is rising. Approximately 700 natural disasters were registered in the last two years effecting 400 million people all around the world. Earthquake is one of the natural disasters which can produce terrible damage. It usually occurs without warning. Sudden slip in Earth's crusts cause earth to shake which can cause mass destruction to the buildings and people in nearby areas. Other effects of Earthquake include damage to property, tsunami and land sliding. Its causes, methods of measurement and scientific discoveries will be discussed in detail in this paper.

General Overview

The surface of the earth is in continuous motion. This is called plate tectonics, the large scale motion of earth's lithosphere that consists of plates. The whole earth's surface consists of these plates. Since these plates are moving, they can rub against each other, sink beneath each other or spread apart from each other. At some places where the motion is not smooth, the plates can strike together at the edges, but the rest of the plates are still moving. As a result, rocks can be distorted from the edges. This distortion causes strain to develop at the edge of the rock. Since the motion is still in progress, a point comes where the strain is developed to such an extent that rock cannot withstand any more bending (SOEST, 2013). As a result, rock breaks, release energy and starts to move again. Earthquake is a result of this sudden release of energy known as seismic waves in the earth's crust. There are three main types of the movement that can cause earthquake: normal, reverse and strike-slip. In normal and strike-slip, the direction of the displacement In fault area is vertical. Whereas in reverse type, movement in the fault area occurs along the horizontal axis.

Methods/Tools Of Study

Seismograph or Seismometer is a device use by scientists to study earthquakes (Michigan Tech,2013). The goal of this device is to accurately record the vibration of the earth caused by earthquakes. The simple seismometer consists of a weight that is attached to the vertically hanging spring so that it is sensitive to ...